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Re: PATCH for 64-bit MIPS ELF buglets
I put in the attached patch. It contains the non-controversial
aspects of the patch I submitted earlier today, as well as an attempt
to restore the behavior of R_MIPS_64 for 32-bit targets. Ian, please
take a look at the mips_elf_relocate_section changes for the details.
I'll work on the R_MIPS16* stuff next.
--
Mark Mitchell mark@codesourcery.com
CodeSourcery, LLC http://www.codesourcery.com
Index: elf32-mips.c
===================================================================
RCS file: /cvs/binutils/binutils/bfd/elf32-mips.c,v
retrieving revision 1.17
diff -u -p -r1.17 elf32-mips.c
--- elf32-mips.c 1999/07/12 07:35:06 1.17
+++ elf32-mips.c 1999/07/12 23:35:07
@@ -67,8 +67,9 @@ struct mips_elf_link_hash_entry
/* External symbol information. */
EXTR esym;
- /* Number of MIPS_32 or MIPS_REL32 relocs against this symbol. */
- unsigned int mips_32_relocs;
+ /* Number of R_MIPS_32, R_MIPS_REL32, or R_MIPS_64 relocs against
+ this symbol. */
+ unsigned int possibly_dynamic_relocs;
/* The index of the first dynamic relocation (in the .rel.dyn
section) against this symbol. */
@@ -678,22 +679,19 @@ static reloc_howto_type elf_mips_howto_t
0x000007c4, /* dst_mask */
false), /* pcrel_offset */
- /* A 64 bit relocation. This is used in 32 bit ELF when addresses
- are 64 bits long; the upper 32 bits are simply a sign extension.
- The fields of the howto should be the same as for R_MIPS_32,
- other than the type, name, and special_function. */
+ /* A 64 bit relocation. */
HOWTO (R_MIPS_64, /* type */
0, /* rightshift */
- 2, /* size (0 = byte, 1 = short, 2 = long) */
- 32, /* bitsize */
+ 4, /* size (0 = byte, 1 = short, 2 = long) */
+ 64, /* bitsize */
false, /* pc_relative */
0, /* bitpos */
complain_overflow_bitfield, /* complain_on_overflow */
mips32_64bit_reloc, /* special_function */
"R_MIPS_64", /* name */
true, /* partial_inplace */
- 0xffffffff, /* src_mask */
- 0xffffffff, /* dst_mask */
+ MINUS_ONE, /* src_mask */
+ MINUS_ONE, /* dst_mask */
false), /* pcrel_offset */
/* Displacement in the global offset table. */
@@ -3766,7 +3764,7 @@ mips_elf_link_hash_newfunc (entry, table
/* We use -2 as a marker to indicate that the information has
not been set. -1 means there is no associated ifd. */
ret->esym.ifd = -2;
- ret->mips_32_relocs = 0;
+ ret->possibly_dynamic_relocs = 0;
ret->min_dyn_reloc_index = 0;
ret->fn_stub = NULL;
ret->need_fn_stub = false;
@@ -5850,6 +5848,7 @@ mips_elf_calculate_relocation (abfd,
case R_MIPS_32:
case R_MIPS_REL32:
+ case R_MIPS_64:
/* If we're creating a shared library, or this relocation is
against a symbol in a shared library, then we can't know
where the symbol will end up. So, we create a relocation
@@ -5862,11 +5861,11 @@ mips_elf_calculate_relocation (abfd,
BFD_ASSERT (h != NULL);
reloc_index
= mips_elf_create_dynamic_relocation (abfd,
- info,
- relocation,
- h->root.dynindx,
- addend,
- input_section);
+ info,
+ relocation,
+ h->root.dynindx,
+ addend,
+ input_section);
if (h->min_dyn_reloc_index == 0
|| reloc_index < h->min_dyn_reloc_index)
h->min_dyn_reloc_index = reloc_index;
@@ -5874,7 +5873,7 @@ mips_elf_calculate_relocation (abfd,
}
else
{
- if (r_type == R_MIPS_32)
+ if (r_type != R_MIPS_REL32)
value = symbol + addend;
else
value = addend;
@@ -5975,10 +5974,6 @@ mips_elf_calculate_relocation (abfd,
value = g & howto->dst_mask;
break;
- case R_MIPS_64:
- value = (symbol + addend) & howto->dst_mask;
- break;
-
case R_MIPS_GOT_PAGE:
value = mips_elf_got_page (abfd, info, symbol + addend, NULL);
if (value == (bfd_vma) -1)
@@ -6178,7 +6173,17 @@ _bfd_mips_elf_relocate_section (output_b
reloc_howto_type *howto;
/* Find the relocation howto for this relocation. */
- howto = elf_mips_howto_table + ELF32_R_TYPE (rel->r_info);
+ if (ELF32_R_TYPE (rel->r_info) == R_MIPS_64
+ && !ABI_64_P (output_bfd))
+ /* Some 32-bit code uses R_MIPS_64. In particular, people use
+ 64-bit code, but make sure all their addresses are in the
+ lowermost or uppermost 32-bit section of the 64-bit address
+ space. Thus, when they use an R_MIPS_64 they mean what is
+ usually meant by R_MIPS_32, with the exception that the
+ stored value is sign-extended to 64 bits. */
+ howto = elf_mips_howto_table + R_MIPS_32;
+ else
+ howto = elf_mips_howto_table + ELF32_R_TYPE (rel->r_info);
if (!use_saved_addend_p)
{
@@ -6303,6 +6308,56 @@ _bfd_mips_elf_relocate_section (output_b
continue;
}
+ if (ELF32_R_TYPE (rel->r_info) == R_MIPS_64
+ && !ABI_64_P (output_bfd))
+ /* See the comment above about using R_MIPS_64 in the 32-bit
+ ABI. Until now, we've been using the HOWTO for R_MIPS_32;
+ that calculated the right value. Now, however, we
+ sign-extend the 32-bit result to 64-bits, and store it as a
+ 64-bit value. We are especially generous here in that we
+ go to extreme lengths to support this usage on systems with
+ only a 32-bit VMA. */
+ {
+#ifdef BFD64
+ /* Just sign-extend the value, and then fall through to the
+ normal case, using the R_MIPS_64 howto. That will store
+ the 64-bit value into a 64-bit area. */
+ value = mips_elf_sign_extend (value, 64);
+ howto = elf_mips_howto_table + R_MIPS_64;
+#else /* !BFD64 */
+ /* In the 32-bit VMA case, we must handle sign-extension and
+ endianness manually. */
+ bfd_vma sign_bits;
+ bfd_vma low_bits;
+ bfd_vma high_bits;
+
+ if (value & 0x80000000)
+ sign_bits = 0xffffffff;
+ else
+ sign_bits = 0;
+
+ /* If only a 32-bit VMA is available do two separate
+ stores. */
+ if (bfd_big_endian (input_bfd))
+ {
+ /* Store the sign-bits (which are most significant)
+ first. */
+ low_bits = sign_bits;
+ high_bits = value;
+ }
+ else
+ {
+ low_bits = value;
+ high_bits = sign_bits;
+ }
+ bfd_put_32 (input_bfd, low_bits,
+ contents + rel->r_offset);
+ bfd_put_32 (input_bfd, high_bits,
+ contents + rel->r_offset + 4);
+ continue;
+#endif /* !BFD64 */
+ }
+
/* Actually perform the relocation. */
mips_elf_perform_relocation (howto, rel, value, input_bfd,
contents);
@@ -6891,6 +6946,7 @@ _bfd_mips_elf_check_relocs (abfd, info,
case R_MIPS_32:
case R_MIPS_REL32:
+ case R_MIPS_64:
if (dynobj == NULL
&& (info->shared || h != NULL)
&& (sec->flags & SEC_ALLOC) != 0)
@@ -6918,7 +6974,7 @@ _bfd_mips_elf_check_relocs (abfd, info,
conservative, we could actually build the GOT here,
rather than in relocate_section. */
g->local_gotno++;
- sgot->_raw_size += 4;
+ sgot->_raw_size += MIPS_ELF_GOT_SIZE (dynobj);
}
switch (r_type)
@@ -6959,6 +7015,7 @@ _bfd_mips_elf_check_relocs (abfd, info,
case R_MIPS_32:
case R_MIPS_REL32:
+ case R_MIPS_64:
if ((info->shared || h != NULL)
&& (sec->flags & SEC_ALLOC) != 0)
{
@@ -6996,7 +7053,7 @@ _bfd_mips_elf_check_relocs (abfd, info,
/* We only need to copy this reloc if the symbol is
defined in a dynamic object. */
hmips = (struct mips_elf_link_hash_entry *) h;
- ++hmips->mips_32_relocs;
+ ++hmips->possibly_dynamic_relocs;
}
/* Even though we don't directly need a GOT entry for
@@ -7189,9 +7246,10 @@ _bfd_mips_elf_adjust_dynamic_symbol (inf
file. */
hmips = (struct mips_elf_link_hash_entry *) h;
if (! info->relocateable
- && hmips->mips_32_relocs != 0
+ && hmips->possibly_dynamic_relocs != 0
&& (h->elf_link_hash_flags & ELF_LINK_HASH_DEF_REGULAR) == 0)
- mips_elf_allocate_dynamic_relocations (dynobj, hmips->mips_32_relocs);
+ mips_elf_allocate_dynamic_relocations (dynobj,
+ hmips->possibly_dynamic_relocs);
/* For a function, create a stub, if needed. */
if (h->type == STT_FUNC